An 8 owner on the international forum had a bit of trouble on the Dyno.
The heater core blew at 165 MPH during a dyno run.
"Wow, I consider myself lucky that it blew when it was straped to the dyno and not on my way home. The steam filled the garage and there was so much scalding antifreeze. First run, 3rd gear 242hp, 259ft/lb tq. We were going for a second run in 4th gear and the dyno was reading a speed of 165mph when the heater core went. "
BTW his '91 850 has about 200,000 miles on the engine. So much for the Terrible V12 engine reputation